A Phase 1/2 trial of SRA737 (a Chk1 inhibitor) administered orally in patients with advanced cancer.

BACKGROUND: This was a first-in-human Phase 1/2 open-label dose-escalation study of the novel checkpoint kinase 1 (Chk1) inhibitor SRA737. METHODS: Patients with advanced solid tumours enrolled in dose-escalation cohorts and received SRA737 monotherapy orally on a continuous daily (QD) dosing schedule in 28-day cycles. Expansion cohorts included up to 20 patients with prospectively selected, pre-specified response predictive biomarkers. RESULTS: In total, 107 patients were treated at dose levels from 20-1300 mg. The maximum tolerated dose (MTD) of SRA737 was 1000 mg QD, the recommended Phase 2 dose (RP2D) was 800 mg QD. Common toxicities of diarrhoea, nausea and vomiting were generally mild to moderate. Dose-limiting toxicity at daily doses of 1000 and 1300 mg QD SRA737 included gastrointestinal events, neutropenia and thrombocytopenia. Pharmacokinetic analysis at the 800 mg QD dose showed a mean Cmin of 312 ng/mL (546 nM), exceeding levels required to cause growth delay in xenograft models. No partial or complete responses were seen. CONCLUSIONS: SRA737 was well tolerated at doses that achieved preclinically relevant drug concentrations but single agent activity did not warrant further development as monotherapy. Given its mechanism of action resulting in abrogating DNA damage repair, further clinical development of SRA737 should be as combination therapy. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov NCT02797964.

MOMENTUM: momelotinib vs danazol in patients with myelofibrosis previously treated with JAKi who are symptomatic and anemic.

Hallmark features of myelofibrosis (MF) are cytopenias, constitutional symptoms and splenomegaly. Anemia and transfusion dependency are among the most important negative prognostic factors and are exacerbated by many JAK inhibitors (JAKi). Momelotinib (MMB) has been investigated in over 820 patients with MF and possesses a pharmacological and clinical profile differentiated from other JAKi by inhibition of JAK1, JAK2 and ACVR1. MMB is designed to address the complex drivers of iron-restricted anemia and chronic inflammation in MF and should improve constitutional symptoms and splenomegaly while maintaining or improving hemoglobin in JAKi-naive and previously JAKi-treated patients. The MOMENTUM Phase III study is designed to confirm and extend observations of safety and clinical activity of MMB.

Lay abstract The most important features of myelofibrosis (MF) are low blood cell counts and symptoms including tiredness, night sweats and itching, along with increased size of the spleen, which may cause a feeling of fullness and pain. Low red blood cell counts (anemia) may mean regular blood transfusions are needed and this is one of the signs MF is getting worse. Drugs called JAK inhibitors (JAKi) are available to treat MF, but can have a side effect of making blood cell counts lower. Momelotinib (MMB) is a different type of JAKi to the ones currently available, and is an experimental drug for MF. MMB is designed to treat symptoms and spleen like other JAKi, but also to improve blood cell counts. MMB has already been given to more than 820 patients with MF in other clinical studies. Some of the patients in these studies had been treated with different JAKi before, and others got MMB as their first JAKi treatment. The MOMENTUM Phase III study is designed to collect more information on the safety and effectiveness of MMB in MF.

A Phase I/II Trial of Oral SRA737 (a Chk1 Inhibitor) Given in Combination with Low-Dose Gemcitabine in Patients with Advanced Cancer.

PURPOSE: This was a Phase I/II trial of the novel checkpoint kinase 1 (Chk1) inhibitor SRA737 given in combination with gemcitabine. Its objectives were to establish the safety profile, recommended Phase 2 dose (RP2D), pharmacokinetics profile, and clinical activity of SRA737. PATIENTS AND METHODS: Patients with advanced solid tumors were enrolled into dose-escalation cohorts and treated in 28-day cycles with oral SRA737 on days 2, 3, 9, 10, 16, and 17, and intravenous gemcitabine on days 1, 8, and 15. Treatment was continued until progression. Each expansion cohort included up to 20 patients with specific genetically defined tumors. RESULTS: The RP2D was determined to be 500 mg SRA737 combined with low-dose (250 mg/m2) gemcitabine. Of 143 enrolled patients, 77 were treated at doses of at least 500 mg SRA737 combined with 250 mg/m2 gemcitabine. Common toxicities of nausea, vomiting, fatigue, and diarrhea were primarily mild to moderate, and rarely led to treatment discontinuation. Anemia, neutropenia, and thrombocytopenia were grade ≥3 in 11.7%, 16.7%, and 10% of patients treated at the RP2D, respectively. The objective response rate (ORR) was 10.8% overall and notably the ORR in anogenital cancer was 25%. Partial tumor responses were observed in anogenital cancer, cervical cancer, high-grade serous ovarian cancer, rectal cancer, and small cell lung cancer. CONCLUSIONS: SRA737 in combination with low-dose gemcitabine was well tolerated with lower myelotoxicity than has been seen at standard doses of gemcitabine or with other combinations of Chk1 inhibitors with gemcitabine. Tumor responses were observed in anogenital and other solid tumors.

Single-dose pharmacokinetic study of rapidly dispersing diclofenac potassium formulations in healthy volunteers.

OBJECTIVE: The clinical utility of diclofenac potassium, a commonly prescribed analgesic that provides mild to moderate pain relief, may be hindered by its delayed, depressed, and/or inconsistent absorption characteristics. A diclofenac potassium formulation using proprietary dispersion technology (ProSorb) was developed to overcome these limitations. The authors evaluated and compared the pharmacokinetics (PK) of 2 investigational diclofenac potassium liquid filled soft gelatin capsule (DPSGC) preparations and one investigational diclofenac liquid formulation, each incorporating the proprietary dispersion technology, to establish bioequivalence and identify a formulation for further clinical study. RESEARCH DESIGN AND METHODS: In an open-label, single-dose, three-way crossover, relative bioavailability study, 24 healthy volunteers were randomized to receive each of the 25-mg DPSGC formulations (development processes A and B) and the 1-mL (25-mg) liquid diclofenac formulation (similar to the fill liquid used in the DPSGC products) during three inpatient visits. Each dose was separated by 3 days. Plasma samples were collected at preselected time points through 6 hours post dose. Diclofenac concentrations were determined using a validated HPLC method. Bioequivalence was established within the 80% to 125% acceptance range. Safety and tolerability were monitored throughout. RESULTS: Area under the plasma concentration-time curves (AUC(0-)(t)) for the three formulations were between 577 and 585 ng-hr/mL and peak plasma concentrations (C(max)) were between 958 and 1087 ng/mL, with the DPSGC process B group having the highest C(max). The times to C(max) (t(max)) were all below 30 minutes, with the liquid formulation producing the shortest t(max) (15 minutes). Plasma concentration-time course profiles were similar for all three rapidly dispersing diclofenac potassium formulations. One mild adverse event was observed (lingual paresthesia) and one participant discontinued due to an unrelated event (acute tonsillitis). CONCLUSIONS: These data show that diclofenac potassium formulations using proprietary dispersion technology are rapidly and consistently absorbed. These characteristics may be beneficial in settings where rapid and consistent drug absorption is desirable. These results may differ in other patient populations such as those experiencing pain or illness.